It’s Amazon Prime time before Christmas, and customers aren’t breaking a sweat

It’s the final countdown for holiday shopping, and based upon your personality, it’s either an impending anxiety attack or a procrastinator’s paradise.

Almost 40 percent of the season’s sales happen in the last 10 days ahead of Christmas, as per the National Retail Federation. And as of last Wednesday, 90 percent of Americans hadn’t done their shopping.

For the procrastinators driving it to the very last minute, you can rely on Amazon “Prime Now,” available to Prime customers in 20 U.S. cities, including Atlanta, Baltimore, Miami, New York City, L.A., Chicago, and San Fransisco. (Last season, “Prime Now” was only offered in New York.)And yes, they’ll deliver until 11:59 p.m. on Christmas Eve.

This is the first year that Amazon Prime offers free two-hour delivery for Prime members. (If you’re really in a hurry for that white elephant present on Christmas Eve, there is a 1-hour delivery option which will cost you $7.99.)

Last March, Amazon hiked its annual Prime membership from $79 to $99. For a few consumers who make shopping on Amazon a regular hobby —and like the extra convenience of “Prime Now” — the $20 does not make much of an impact. But the increase actually compelled Sasha and James Arnold to give up their Prime membership entirely. On the other hand, Sasha, 28, asserted she managed to buy all of her gifts or necessities online, mostly on Amazon.

”We try to do all of our gift shopping about two weeks in advance, just to be safe. Honestly though, there’s never anything that’s so urgent that we’d need two-day delivery,” she says.

However, this season, in order to avoid any late arrivals, the Arnolds asked a friend using Prime membership to buy it on their behalf and paid him for the value of the item.

Erin Meyers, 42, has a Prime account and a couple of young daughters. “I definitely need to do some last-minute shopping, which will be happening over the next day or two. I buy mostly everything, including toys, books, shoes and coats for the kids, on Amazon. Every once in awhile deliveries have arrived later than anticipated, but I pretty much trust it 99 percent of the time,” she says.

An Amazon spokesperson said in spite of the busy holiday season, customers can anticipate the same expediency: “Amazon customers can find tens of millions of items available with Free Shipping, every day because fast free shipping is a commitment we make to customers 365-days a year.”

Vincent Mirabella, 38, who also has two young daughters, says he relies upon Amazon for most of his Christmas shopping. He doesn’t have a Prime account but plans far enough in advance to have his gifts on time. “After a long day at work when I’m drinking a beer at the bar, I just order all my gifts within a few minutes and don’t have to worry about a thing,” he says.

Shopping online would require a way of planning, which isn’t something Glenn Collins, 57, says he has. “We’re so unorganized that we just end up going to the local places and buy unnecessary gifts. If we were more organized, we’d buy online,” he says.

For others, like Brad Alford, 51, the in-store shopping experience is basically more preferable than buying online — although it will take more time. ”For us, it’s just as convenient to buy in stores. We still do it that way, I guess I’m old-fashioned. But I can definitely see myself using Amazon more and more in the future,” he says.

Today, Amazon has become a house-hold name. Macquarie Securities Group analyst Ben Schachter forecasts it’ll only become a more substantial part of everyday shopping. He is expecting the Seattle Company’s share of U.S. eCommerce to grow 4 percent in 2015 to 26 percent. He attributed the boosts to Prime, with members at present making up 25 percent of the total U.S. households and estimated to increase to half of all U.S. households by 2020.